Lua Syntax highlighting breaks, if there is a single quote (') in the comment line.

[yssource]

function hello()
end

-- test with single quote ' ine comment line

function world()
end

[yssource]

Sorry, It's caused by my personal user-config. (add-hook 'prog-mode-hook #'(lambda () (modify-syntax-entry ?- "w")))

The dash is the comment mark in lua-mode, after commenting out the line, the syntax highlighting works well.